v5.0.x: prepare v5.0.9rc1 release

- Update VERSION file to v5.0.9rc1 with correct date (23 September 2025)
- Update NEWS with actual changes from v5.0.8 to v5.0.9rc1 including:
  * PMIx v5.0.9 and PRRTE v3.0.12 updates
  * GPFS 5.2.3-0+ support
  * OFI accelerator memory enhancements
  * Critical PML OB1 bug fix for memory overruns
  * Fortran string conversion fixes
  * Threading improvements
  * Various documentation and build system fixes

Signed-off-by: Tomislav Janjusic <[email protected]>

Author: janjust

VERSION

@@ -41,7 +41,7 @@ flex_min_version=2.5.4
 # requirement is that it must be entirely printable ASCII characters
 # and have no white space.
 
-greek=a1
+greek=rc1
 
 # If repo_rev is empty, then the repository version number will be
 # obtained during "make dist" via the "git describe --tags --always"
@@ -62,7 +62,7 @@ tarball_version=gitclone
 
 # The date when this release was created
 
-date="30 May 2025"
+date="23 September 2025"
 
 # The shared library version of each of Open MPI's public libraries.
 # These versions are maintained in accordance with the "Library

docs/release-notes/changelog/v5.0.x.rst

@@ -4,6 +4,33 @@ Open MPI v5.0.x series
 This file contains all the NEWS updates for the Open MPI v5.0.x
 series, in reverse chronological order.
 
+Open MPI Version v5.0.9rc1
+------------------------------
+:Date: 23 September 2025
+
+- Internal PMIx and PRRTe versions:
+  - PMIx (v5.0.9). Repo: ``https://github.com/openpmix/openpmix``. Commit hash: ``b357357c09915779eabd362f6857f61b41680329``.
+  - PRRTE (v3.0.12). Repo: ``https://github.com/openpmix/prrte``. Commit hash: ``b357357c09915779eabd362f6857f61b41680329``.
+
+- Functionality Enhancements
+  - GPFS: Added support for GPFS 5.2.3-0 and newer versions
+  - OFI: Enhanced accelerator memory support with proper rcache flag handling
+  - OFI: Added memory monitor export for better memory management
+  - ROCm: Added missing header for memcpy operations in accelerator component
+
+- Bug Fixes and Minor Enhancements
+  - PML OB1: Fixed critical bug in MCA_PML_OB1_ADD_ACK_TO_PENDING that could cause memory overruns or allocation failures
+  - Fortran: Fixed off-by-one string copy error in C2F string conversion
+  - Fortran: Fixed ompi string c2f conversion when Fortran string length is less than C string length
+  - Threading: Fixed OMPI_MPI_THREAD_LEVEL environment variable handling to allow useful overrides in threaded library use cases
+  - Threading: Enhanced OMPI_MPI_THREAD_LEVEL to accept both numeric (0-3) and string ('multiple', 'MPI_THREAD_MULTIPLE', etc.) values
+  - OSC: Fixed rdma component when not using ob1 PML
+  - S390x: Fixed alignment of opal_atomic_int128_t to be 16-byte aligned
+  - Configury: Improved Fortran complex(real16) testing and module file cleanup
+  - Documentation: Fixed MCA environment variable prefix documentation for PRRTE
+  - Documentation: Updated MPI_Init*/MPI_Finalize*/MPI_Session_* man pages with numerous improvements
+  - Build system: Removed whitespace from conftestval-style tests and cleaned up configuration
+
 Open MPI Version v5.0.8
 ------------------------------
 :Date: 30 May 2025